There exists a wide variety of substances such as a substance lethal to plants and a substance effective in slowing plant growth. Hereinafter, the substance lethal to plants and the substance effective in slowing plant growth are generally referred to as a substance having a harmful effect on plant growth or a growth inhibitor.
For example, use of agrochemicals, growth regulators, fertilizers, or materials, which have been used for agriculture and horticulture, may cause a harmful effect on plants treated with the above compounds. This phenomenon is generally called herbicide injury and/or fertilizer injury. In addition, it has been known that microbes, arthropods, animals such as nematodes, and even other plants may produce a growth inhibitor to exert a harmful effect.
In order to circumvent this harmful effect, plants have measures against such a growth inhibitor. Examples of the measures include rendering the above substance harmless by detoxifying and metabolizing the substance, reducing uptake and incorporation of the substance, and promoting export of the substance. Among the particularly important measures is an activation of a function of detoxifying and metabolizing the substance. Examples of a known molecular species involved in such detoxification and metabolism include a cytochrome P450 having a monooxygenase activity (Non Patent Literature 1). Meanwhile, 350 or more members of rice P450 and 240 or more members of Arabidopsis P450 have been identified (Non Patent Literature 2). Unfortunately, a whole picture of the mechanism of detoxifying and metabolizing a growth inhibitor by a cytochrome P450 remains unresolved.
Accordingly, some of the mechanism of detoxifying and metabolizing a growth inhibitor by a cytochrome P450 are tried to be revealed. This can facilitate, for example, giving a desired plant the resistance to the growth inhibitor. Also, if a cytochrome P450 gene involved in the detoxification and metabolism of a particular growth inhibitor is identified, it is possible to provide a method for transformation using the cytochrome P450 gene as a selection marker.